Vacuum connection ICT 34

[james_stan]

My bus has an 009 at present which I've had no real issues with, however I also have in a box
another dissy I fancy trying out (043 905 205) http://www.oldvolkshome.com/ignition.htm#A1974MFD. Do people think it's ok to make a vacuum connection by T-ing into my balance pipe that runs between the manifolds ?

Cheers

James

 

[sparkywig]

There's a vacuum connection on the left hand carb.

 

[bac2ba6]

^^WHS^^ got 34icts and a vac dizzy ! easiest one is the left hand carb just above where the manifold bolts to the carb there a brass
port for the vacuum take off

 

[james_stan]

Ah, that'll be teh bit I blanked off during installation then..

Anyone any idea of the suitability of that distributor ? Apparently orignally fitted to 1600 Beetle Manual in the mid 70's..

Cheers

JS

 

[Trikky2]

Provided its in good shape that dissy will do fine

 

[james_stan]

Provided its in good shape that dissy will do fine

Seems OK. The plate moves when I suck hard on the vacuum can. Any other checks I can make ?

Cheers

James

 

[Trikky2]

Check for lateral (sideways) play on the dissy shaft top and bottom. Make sure the bearings are lubricated.

Check there isnt excessive wear on the lobes that operate the points - sometimes previous owners have neglected to put a smear of grease on them.

Check the weights and springs (under the points plate) are in good condition and lubricated.

Check the shaft with the rotor on it can move on the main shaft, it should move and spring back as the weight springs pull it back into place.

The main wear point is the base plate (the bit that moves when you suck the vac can). This plate should move easily. You can check by unhooking the vac can arm and moving the plate by hand. If its stiff then oil it and work it back and forth till it moves smoothly. If its loose and can move laterally eg. there is sideways play on the base plate, then the dissy is worn and should not be used in this condition, since your timing will jump all over the place when running.

 

[james_stan]

Thanks Trikky - I'll disect it tonight and see how it looks.

Cheers

James

 

[james_stan]

Check for lateral (sideways) play on the dissy shaft top and bottom. Make sure the bearings are lubricated.

Check there isnt excessive wear on the lobes that operate the points - sometimes previous owners have neglected to put a smear of grease on them.

Check the weights and springs (under the points plate) are in good condition and lubricated.

Check the shaft with the rotor on it can move on the main shaft, it should move and spring back as the weight springs pull it back into place.

The main wear point is the base plate (the bit that moves when you suck the vac can). This plate should move easily. You can check by unhooking the vac can arm and moving the plate by hand. If its stiff then oil it and work it back and forth till it moves smoothly. If its loose and can move laterally eg. there is sideways play on the base plate, then the dissy is worn and should not be used in this condition, since your timing will jump all over the place when running.

OK had it apart tonight

* Shaft play perceptible but small a couple of thou, four maybe ..

* Lobes seem good no wear ridge from the points

* Weights well lubricated - still a good covering of original factory brownish grease I think.
Points plate though a real pain to get out and worse to get back in. An interference fit I think they call it.

* Rotor bit moves independantly from input shaft.

So apart from some slight shaft play I think we're good to give it a try !

Am only getting approx 18 degs advance with the 009 so hopefully this will give more
better spread.

Cheers

JS

PS might running low advance say max 25 BTDC give a poorer burn and contribute to a rich petrol smelling exhaust ?

 

[Trikky2]

Good news Sounds like the dissy is a good un.

Yes insufficient advance will cause poor combustion/wasted fuel. It can also cause the engine to run hotter than normal and puts a fair bit more heat into the exhaust valves and exhaust sytem at higher revs. I think you may find a considerable improvement in both performance and mpg if the current dissy is supplying so little advance.